Study on the arc erosion resistance and mechanism of Cr- doped W Cu composites

WCu composites have been widely used in electrical contacts and arc resistance electrodes. To improve the arc erosion resistance, the WCu composites doping Cr was fabricated by high energy ball milling and SPS process. The arc erosion characteristics of W-Cu-Cr composites under 1000, 5000 and 10,000 electric contact operations were studied, and the mechanism of arc erosion resistance of WCu composites doped with Cr was revealed. The results indicated that the average arc energy of W-Cu-1Cr composites decreased by 35.7%, 53.7%, and 63.8% respectively after 1000, 5000, and 10,000 electrical contact tests compared with WCu composites undoped Cr phase. After 10,000 operations, the average welding force of W-Cu-1Cr composites is 24.3% lower than that WCu composites undoped Cr phase, and had lower arc erosion loss (0.57 mg). In addition, the strong oxygen absorption of Cr phase results in the formation of an oxide film on the surface of WCu composites. The arc root moves smoothly and continuously along the Cr2O3 oxide film at the grain boundary, thereby reducing arc energy and improving the arc erosion resistance of WCu composites.